Date of Award

2017

Degree Type

Thesis

Degree Name

Honors Thesis

Department

Pharmacy

First Advisor

Mikaela Drake

Abstract

Background

Coronary artery disease (CAD) results from the buildup of cholesterol, inflammatory factors, and proliferating smooth muscle cells within a vessel wall. This plaque impedes on the vessel lumen, decreasing the space through which blood can flow, leading to an array of complications in the human body. To offset these effects, the arterial wall undergoes outward remodeling, a compensatory physiologic phenomenon that blood vessels undertake when burdened with a blockage, such as CAD. In a previously conducted study, a coronary epicardial adipose tissue excision (cEATx) surgery was performed above the left anterior descending (LAD) in Ossabaw swine to investigate the effects of local adipose on the progression of CAD. Compared to the sham control group, pigs that underwent the adipectomy procedure revealed focal attenuation of disease progression at the surgical site within the LAD. Unlike, the previous research question, this current study aims to determine if there was an additional global outward remodeling effect by investigating disease progression in the right coronary artery (RCA) of the same animals. By comparing the two sites, we are able to determine whether the outward remodeling observed in the LAD was due to the local surgical procedure or a physiologic compensation for limitations caused by CAD progression.

Methods

Images of the RCA lumen were collected using intravascular ultrasound (IVUS). Measurements of the external elastic lamina and lumen area were taken of each collected still-frame image. For each pig, the data were averaged across the proximal 15 mm of the RCA at two separate time points (pre- and post-surgery). Pre-surgery measures were obtained the day the surgery took place while post-surgery measures were obtained 3 months later. Percent stenosis, plaque area, outward remodeling, and lumen area were all assessed.

Results

Progression of CAD in the RCA, represented by percent stenosis, was not significantly slowed in the adipectomy pigs compared to the control group. Outward remodeling in the RCA, represented by an increase in external elastic lamina circumference, was not significantly higher in the adipectomy pigs compared to the control group.

Conclusions

These data indicate that the cEATx procedure at the LAD did not attenuate CAD progression in the RCA.

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